FoxNews on August 24, 2014, published a Space.com contribution on engine technology being developed for a British space plane also could find its way into hypersonic aircraft built by the U.S. military. Excerpts below:
The U.S. Air Force Research Laboratory is studying hypersonic vehicles that would use the Synergetic Air-Breathing Rocket Engine (SABRE), which the English company Reaction Engines Ltd. is working on to power the Skylon space plane, AFRL officials said.
“AFRL is formulating plans to look at advanced vehicle concepts based on Reaction Engine’s heat-exchanger technology and SABRE engine concept,” officials with AFRL, which is based in Ohio, told Space.com via email last month.
SABRE and Skylon were invented by Alan Bond and his team of engineers at the Abingdon, England-based Reaction Engines.
SABRE burns hydrogen and oxygen. It acts like a jet engine in Earth’s thick lower atmosphere, taking in oxygen to combust with onboard liquid hydrogen. When SABRE reaches an altitude of 16 miles and five times the speed of sound (Mach 5), however, it switches over to Skylon’s onboard liquid oxygen tank to reach orbit. (Hypersonic flight is generally defined as anything that reaches at least Mach 5.)
Two SABREs will power the Skylon space plane — a privately funded, single-stage-to-orbit concept vehicle that is 276 feet long. At takeoff, the plane will weigh about 303 tons.
Bond’s team has also successfully tested the pre-cooler for a problem aviation jet engines have to deal with: foreign objects being sucked in.
“We know it [the pre-cooler] can take debris, insects, leaves,” Bond said.
Bond estimates that the pre-cooler is now at a technology readiness level (TRL) of about 5. NASA and AFRL use a 1-to-9 TRL scale to describe a technology’s stage of development. According to NASA’s TRL descriptions, 5 represents “thorough testing” of a prototype in a “representative environment.”
The AFRL work is being carried out under a Cooperative Research and Development Agreement (CRADA) with Reaction Engines that was announced in January. AFRL officials told Space.com that they are using computers to model SABRE.
Bond declined to confirm rumors of organized support within the U.S. aerospace community that involves former senior program managers of the U.S. military’s most high-profile defense projects.
Bond sees Skylon as an international project that would include the U.S. and Europe.
“We’re in dialogue with people across Europe in regard to supplying [rocket engine components]. We don’t want to reinvent the wheel; we’d like to be the engine integrator and put it on our test facilities and run it,” he explained.
Two SABRE engines are expected to be tested in 2019. “Hopefully, the earlier part of 2019,” Bond said. “I’d like to feel we can test them on Westcott. That is where the rocket propulsion establishment used to be.”
The SABRE development program is expected to cost 360 million British pounds ($600 million at current exchange rates). “We’ve got 80 million [British pounds] of the 360 million lined up. We’re well on our way to that,” Bond said.
Of the 80 million pounds, 60 million is from the U.K. government. As with the commercial ventures NASA supports, Reaction Engines has to meet milestones to acquire those government funds.